Antar trataka — internalised after-image

Close your eyes after gazing and hold the mental image of the flame at the brow centre.

Why it works

The retinal after-image is a real neurological imprint that briefly substitutes an external object for an internal one. Sustaining attention on this fading image trains the mind to hold a mental object steady — the core skill needed for concentration (samatha) meditation more broadly. It bridges outer-object and purely inner-object practice.

How to do it

1. After a round of external gazing, gently close the eyes.
2. Locate the complementary-colour after-image — usually orange-blue — and hold attention there.
3. When the image fades, resist opening the eyes immediately; try to reconstruct it mentally.
4. Note when the mind wanders and bring attention back to the imagined flame without self-criticism.

Evidence

Retinal after-images are well-characterised physiologically. Using them as a meditation object mirrors the "mental image" instruction in samatha traditions, which has modest empirical support for improving sustained attention. (mechanistic)

No trials test antar trataka specifically; evidence borrows from the broader concentration-meditation literature.

Common mistake

Immediately opening the eyes when the image fades, losing the transition from outer to inner attention that is the point of the practice.